We still do not know where the urge for truth comes from; for as yet we have heard only of the obligation imposed by society that it should exist: to be truthful means using the customary metaphors—in moral terms: the obligation to lie according to a fixed convention, to lie herd-like in a style obligatory for all. Now man of course forgets that this is the way things stand for him. Thus he lies in the manner indicated, unconsciously and in accordance with habits which are centuries' old; and precisely by means of this unconsciousness and forgetfulness he arrives at his sense of truth.

Nietzsche.

On Truth and Lie in an Extra-Moral Sense https://web.archive.org/web/20180625190456/http://oregonstat...

> 8 billion people wake up every morning never questioning why are they here, why are they born?

People question this all the time

> No One knows that´s the point. Is truth a constant or a personal definition! From the begining of times to now, no One knows.

I don't think this is a well defined question. Definitions aren't found in nature or the laws of science, but objects that we define and introduce into a logical context. There may be multiple, contradictory definitions of a word. That is fine, as long as you pick one, and you're clear about which one you picked.

You have truth until someone finds a counter example, which can be ignored. So, truth is just a matter of conventions shared by humans.

> Is truth a constant or a personal definition!

It always has been what you believed in.

E.g. at 1 point the Earth was flat. Now it's round. 100s of years later maybe it's a Hexagon.

The so-called knowledge and backing all come back to certain assumptions holding and that's based on the knowledge today. It's not real real reality. For all we know we could be in a game simulation and there are real real humans pulling the strings.